* {
    margin: 0;
    padding: 0;
  }
  
  li {
    list-style: none;
  }
  
  .outbox {
    width: 80%;
    height: 100%;
    margin: 0 auto;
    overflow: hidden;
    // 导入导出按钮
    .top_top{
      button{
        width: 100px;
        height: 30px;
        font-size: 16px;
        margin-top: 20px;
        margin-left: 10px;
      }
    }
    .top {
      width: 100%;
      text-align: center;
      h1{
        padding: 15px;
      }
    }
  
    .mainbox {
      width: 100%;
      display: flex;
      justify-content: space-evenly;
      flex-wrap: wrap;
  
      .classmate {
        margin: 8px;
        width: 150px;
        height: 60px;
        color: #fff;
        text-align: center;
        line-height: 60px;
        border-radius: 6px;
        font-size: 18px;
      }
    }
  
    .foot {
      width: 50%;
      margin: 60px auto;
      display: flex;
      align-items: center;
      justify-content: space-between;
  
      .btn {
        width: 120px;
        height: 50px;
        font-size: 18px;
      }
      .btnTrue{
        width: 120px;
        height: 50px;
        font-size: 18px;
        border: 1px solid red;
        background-color: red;
        color: white;
      }
    }
  }